The cloud presents many opportunities to use APIs for acquiring virtual hardware resources, servers, storage volumes and networking. This talk will show how to create a very big cluster of MongoDB sharded replica sets with the many considerations required for its operation coded using Chef. The talk will go over using Chef to provision AWS resources, managing secrets and shared data using data bags and vault, and the operations aspects of managing a large MongoDB cluster. These are lessons we learned creating such a cluster for a client who wanted to move from using a MongoDB as a service to their own servers in AWS.